1. Technical Field
The present invention relates to data processing units, and particularly, to a data processing unit that allows users to search for desired data from high volumes of data.
2. Related Art
Image processing units of personal computers or the like have become capable of storing high volumes of image data with increasing capacity of hard disk drives. However, when high volumes of image data is stored in a hard disk drive, it is difficult for the user to find out desired data from the hard disk drive. Particularly if a desired image is taken two or three years ago, the user does not often remember the year the image is taken.
Therefore, a method of displaying pictures on a calendar has been proposed as a method for search. In this case, the user finds out a picture taken on a specific date from the pictures displayed on the calendar. However, it is actually difficult for the user to remember the date. Moreover, the calendar representation makes it difficult to find the picture from several years, and thus complicating the operation therefor.
Particularly, photography enthusiasts sometimes take pictures at similar time and location (seasonal pictures such as those of cherry and snow), and thus desire to compare or search for them across several years. However, such searching across several years needs complicated operations including designation of search criteria one by one.
To improve the convenience for image search, JP-A-2000-41209 discloses a method of filing image data in advance and hierarchically organizing them. However, this method requires the user to group image data in advance. Moreover, the searching efficiency depends a lot on whether the grouping is adequate or not.
For search for character information, as disclosed in 2000-132555, the user can designate the accuracy of keyword searching to the accuracy of search criteria input by the user by designating the degree of ambiguity. In contrast, for image search, it is extremely difficult for the user to designate search accuracy to the accuracy of the search criteria input by the user.
Furthermore, in image search, it is necessary to notify the user of the distribution of images to the date the images taken in one way or another. However, when the number of images increases or when the range of the date images taken expands, it becomes difficult to display the distribution of the numbers of images for intuitive graphic user interface.
Such problems are not confined to image data but also for various kinds of data.